Recently a theist asked how an atheist justifies the use of logic. (The following discussion is primarily drawn from strongatheism.net.) The context of the question carries a large number of spurious presuppositions that have origin in a broad scoped fallacy not unique to theism. This fallacy is called the epistemological reversal of the subject-object of thought reversal. (Objectivism defines and discusses this fallacy at length.) Theists imagine a strawman that logic and what is fallaciously identified as the “laws of nature” are “an effect of random molecules and chemical reactions that can never give nor validate anything whatsoever.” Nothing could be further from the truth.

Logic arises from material existence and is necessary for human understanding. Logic is ultimately derived from the Law of Identity, A=A. The nature of physical material existence is that every thing that exists has a specific set of characteristics. [*]

Logic (nor the uniformity of nature) transcend existence, for existence is all that exists. Consider the following syllogism.

a. Logic is necessary for human understanding.b. If theism is true, then divine creation obtains.c. If divine creation is true, then all in existence is contingent to God’s act of creation, and nothing in existence is necessary.d. If theism is true, then logic cannot be necessary. (from b and c)e. Theism is false. (from a and d)

Theists attack premise c by declaring that if logic is part of God’s nature, then its existence is a necessary consequence of divine causation. They may think this an easy escape from the problem, since they imagine God is a necessary entity from a theological standpoint, but it suffers from several unresolvable problems.

1. Theists often assert that non-believers borrow logic from the Christian worldview. This is absolutely irrelevant to the issue at hand, for it does not address the fact that logic becomes subjective if a consciousness creates it. The theist is only specifying the nature of that subjectivity. By so doing he is in fact supporting the argument above. Asserting logic is part of God’s nature does not change the fact that by so doing is to declare it originates from a consciousness, not from objective existence – which is the very definition of subjective. (This is an example of the subject-object reversal. Reality is objective. The imagination is subjective. By claiming logic is subjective, the theist reverses the epistemic priority of objective reality over subjective imagination.)

2. Theistic believers often discuss the nature of their imagined ruling consciousness, but they have absolutely no grounds for discussing the specifics of God’s nature for two reasons.

First, by acceptance of a fantasy God as Sovereign and Creator, the believer cannot assume anything about its properties any more than we can posit “complete entropy” of a system and then try to define physical properties thereof. The theist cannot refute the possibility that a fantasy of an infinite god or a malevolent spirit being is deluding her into believing the statement “God’s nature is logical. Under theism a person can no longer refute arguments based on extreme skepticism. The theist can only refute the idea of an invisible magic entity manipulating their mind, or being the victim of mental illness if her worldview entails self-contained existence.

Second, to discuss what she thinks is God’s nature, she must presume to have knowledge of that nature. Knowledge, however, is rooted in reality and is held in conceptual form.

“To form a concept, one mentally isolates a group of concretes (of distinct perceptual units), on the basis of observed similarities which distinguish them from all other known concretes (similarity is “the relationship between two or more existents which possess the same characteristic(s), but in different measure or degree”); then, by a process of omitting the particular measurements of these concretes, one integrates them into a single new mental unit: the concept, which subsumes all concretes of this kind (a potentially unlimited number). The integration is completed and retained by the selection of a perceptual symbol (a word) to designate it. “A concept is a mental integration of two or more units possessing the same distinguishing characteristic(s), with their particular measurements omitted.” - Leonard Peikoff, “The Analytic-Synthetic Dichotomy”, “Introduction to Objectivist Epistemology”, 131.

The only way to have perceptual knowledge is via our sensory experience. “Man’s senses are his only direct cognitive contact with reality and, therefore, his only source of information. Without sensory evidence, there can be no concepts; without concepts, there can be no language; without language, there can be no knowledge and no science.” – (Ayn Rand, "Kant Versus Sullivan", "Philosophy: Who Needs It", 90.) Since theism’s fantasy of a God cannot be detected by any means of sensory experience or instrumentation, it is impossible for any religious mystic to have perceptual information that can be used as isolated distinct perceptual units that can be the basis of a concept of God. Thus theism’s claim to have knowledge of the nature of God is patently false.

3. The theistic point that “logic is rooted in the nature of God” is a complete ad hoc rationalization: nothing about the notion of a god indicates that it must be necessarily logical or rational. Humans are capable of being both logical and illogical, it is clearly impossible for a more powerful being to not be able to do such a simple thing as make an illogical proposition.

4. Even if it was the case that a God actually existed and its nature was logical, there would be no necessary (in the sense of system K modal logic meaning it is not possibly false) relation between God’s inherent properties and its creation. A burden of proof is upon the God believers to prove their assertion that it necessarily is the case that a relation between what they imagine as God and objective reality obtains such that the basal attributes of their God transfer to objective reality by virtue of a creative action. Without such evidence sufficient to establish the thing as true, the assertion that “logic is rooted in the nature of God” cannot have any weight. The believers would need to prove that powerful beings are restricted in their creations to transferring their basal attributes to that which is created. Were the theist successful in such an endeavor, the religious house of cards would fall to the old rejoinder that a perfect creator cannot create an imperfect creation.

5. It is impossible to make sense of the proposition that “logic is part of God’s nature”. That this is so can be observed by taking note of the Transcendent Argument for God. TAG proposes that “logic is both dependent on God and necessary. ….. If logic is dependent on God it must be contingent. If logic is contingent then it is not a necessary part of human understanding. But logic is a necessary part of human understanding. Thus logic cannot be dependent on God since there is nothing inconsistent about denying the existence of God but there is in denying the principles of logic.” – (Michael Martin: “Butler's Defense of TAG and Critique of Tang” - http://www.infidels.org/library/modern/michael_martin/butler.html). Logic cannot both be an intrinsic part of God’s actions and created by God.

6. Theism’s assertions are self-defeating. If logic existed first as a property of God, then it is a non-material principle, and divine causation is not necessary for its transference at all. All it would prove, at best, is that a non-material principle is involved, but there is a definite lack of specificity in theism’s claim. How is it that some properties of God’s nature are transferred to reality, but others are not? Theism’s claim that “our belief in logic is rooted in the nature of God and evidenced in creation itself” implies that it is logically necessary for one property of the nature of the alleged God to transfer to reality but that other predicated properties do not transfer. Why is that? The theist bears a burden of proof here to show why their case for logic transference does not also entail that their God’s alleged goodness, intelligence, order, morality, self-knowledge, sovereignty, power, justice, etc are also transferred by the creative act. In no sense is the burden of proof fulfilled by simply asserting the contrary position as a mystery.

7. Theism presumes that it makes sense to speak of logic as a non-material entity, which indicates a commitment to idealism. From my perspective, logic is an axiomatic fact of reality, and arises because of the fundamental nature of the material world. It makes no sense to speak of logic dissociated from the material world, any more than it makes sense to speak of immaterial consciousness.

[*] This is a consequence of spontaneous symmetry breaking form Gauge Invariance that occurred during or just prior to the inflationary epoch and cosmic reheating – The Conversion of Inflationary Potential Energy Into Matter. These were random processes as is readily seen from observation of the Cosmic Microwave Background – Blackbody Radiation.

The blackbody CMB and the acceleration of Universal Expansion means that the Big Bang was very much like a black hole singularity in that it was “maximally chaotic involving complete entropy. It implies that the big bang singularity behaves in a completely unpredictable manner in the sense that no physical laws govern its behavior. The unpredictability that pertains to Hawking's principle of ignorance is an unpredictability that is a consequence of lawlessness, not of human inability to know the laws. There is no law, not even a probabilistic law, governing the singularity that places restrictions on what it can emit.Hawking writes that

A singularity can be regarded as a place where there is a breakdown of the classical concept of space-time as a manifold with a pseudo-Reimannian metric. Because all known laws of physics are formulated on a classical space-time background, they will all break down at a singularity. This is a great crisis for physics because it means that one cannot predict the future. One does not know what will come out of a singularity. – [S. W. Hawking, Breakdown of Predictability in Gravitational Collapse,' Physical Review D, 14 (1976), 2460.]

Deterministic or even probabilistic laws cannot obtain on the quantum level in the singularity, since there is no quantum level in the singularity; the space-time manifold that quantum processes presuppose has broken down. The singularity is a violent, terrifying caldron of lawlessness.” – “A Big Bang Cosmological Argument For God's Nonexistence” (1992) Quentin Smith; http://www.infidels.org/library/modern/quentin_smith/bigbang.html

(This also means that no ordering was applied to existence from outside of existence in the time after the Big Bang. But such ordering is required for the theist to assert the anthropic coincidences are evidence of an intelligent creator/designer. Classic hot big bang cosmology was, therefore, the death knell for theism.)